In managed forests, there is an ongoing need to be able to inventory the types of trees that are growing in a given area. For example, in conifer forests, hardwood trees may be initially be viewed as an undesirable species that should be removed because they compete for water and nutrients with a desired species. However, if the hardwoods grow to such a size that they become harvestable, then the trees have their own value and should be inventoried.
As managed forests become increasingly large, it is too costly to physically inventory all the areas of the forest. Therefore, remote sensing technology is becoming increasingly used to provide information about the types and ages of trees that are in the forest.